The present invention relates to a process for preparing a carbon/carbon composite preform and a carbon/carbon composite.
A carbon/carbon composite is a material having unique properties, for example, maintaining high strength and high elastic modulus even at such high temperatures as higher than 1,000.degree. C. and exhibiting only a small thermal expansion coefficient. Its utilization as parts of aeronautic and space machinery and devices, brakes, furnace materials, etc. is expected.
As to the shape of an aggregate of carbon fibers which is used in the preparation of such carbon/carbon composite, two-dimensional fabrics are mainly used, and three-dimensional fabrics are also used as the case may be. Although the use of these fabrics affords carbon/carbon composites of high strength, the structure of the fabrics and the method for preparing them are complicated and the production thereof costs high.
On the other hand, in the case of using carbon fibers which are in the form of short fibers, such as chopped strands, there usually is not obtained a satisfactory reinforcing effect.
Further, in the case of performing a densifying process for preparing a carbon/carbon composite using any of such Fabrics or short fiber-like fibers, it is necessary to provide a separate process for fixing carbon fibers to each other using pitch or a thermosetting resin (binder). This process is one cause of deteriorating the productivity in the carbon/carbon composite preparing process.
It is the object of the present invention to provide a process for preparing a carbon/carbon composite without using expensive carbon fiber fabrics.